Cardiac myocyte adenosine receptors and caveolae

The purine nucleoside adenosine exerts numerous effects in the mammalian he art, the most well-recognized being regulation of coronary blood flow and c ardiac conduction. These effects are mediated via activation of G protein l inked adenosine receptor subtypes, A(2a), and A(1) receptors, located prima rily on vascular cells and cardiac myocytes, respectively. Although adenosi ne A(1) receptors are also expressed in ventricular myocytes, adenosine exe rts no significant direct effects in these cells. A recent report from our laboratory indicates that ventricular myocyte A(1) receptors are concentrat ed in caveolin enriched plasma membrane microdomains referred to as caveola e. This review focuses on these recent findings and their relevance to subc ellular compartmentalization of A(1) receptor signaling in ventricular myoc ardium. (Trends Cardiovasc Med 2001; 11:259-263). (C) 2001, Elsevier Scienc e Inc.